In the construction industry, there are many different types of cement available that can be used in construction depending on the needs of the builder. One common type of cement found in building construction is masonry cement, this type of cement is made from naturally occurring cementitious clays, lime, and silica.
What is cement?
Cement is a binder, a substance that sets and hardens independently, and can bind other materials together. In building construction cement is the most important material to have been developed since ancient times.
The two major cement types are ordinary Portland cement (OPC) which makes up about 90 percent of all cement production worldwide, and the quickly growing non-Portland cement which includes calcium aluminate cement (CCA), geopolymers which were first developed in the 20th century. Ordinary Portland cement accounts for approximately 5 to 10 percent of world cement production while non-Portland cement accounts for about 95 percent. Ordinary Portland cement (OPC) is the most common type of cement used for building construction worldwide. It has been developed since ancient times. It creates carbon dioxide as a by-product, making it friendlier than other cement variants with environmental benefits. Non-Portland cement (NPC) and some other cement such as calcium aluminate cement (CCA), which include fly ash, slag cement, and blended cement were first developed in the 20th century.
Different types of cement
There are different types of cement commonly used in building construction which may include the following:
- Ordinary Portland Cement (OPC)
- Portland Pozzolana Cement (PPC)
- Hydrographic cement
- Rapid Hardening Cement
- Sulfates resisting cement
- Quick setting cement
- Low Heat Cement
- Expansive cement
- Blast Furnace Slag Cement
- High Alumina Cement
- White Cement
- Colored cement
- Air Entraining Cement
- Masonry cement
Different types of cement and their uses
Below are the different types of cement used in the construction industry.
Ordinary Portland Cement (OPC)
Ordinary Portland cement is a type of cement used worldwide in construction applications. It’s made up of calcined clinker (i.e., calcium oxide with small additions of silicon, aluminum, and iron), gypsum (hydrated calcium sulfate), and halite (rock salt). Calcination is the process by which materials are partially heated to very high temperatures in an airless furnace without melting. Halite, also known as rock salt, is added to ordinary Portland cement because it lowers the temperature at which the clinker melts during production.
There are four types of ordinary Portland cement grades:
- Type I: Type I is the highest quality and has a relative compressive strength of 95-105 MPa (i.e., megapascals).
- Type II: Type II has a relative compressive strength of 90-95 MPa and is used in moderate to high-strength concrete applications.
- Type III: Type III has a relative compressive strength between 80 and 90 MPa and is commonly used when the concrete will be subjected to freezing conditions.
- Type IV: Type IV ordinary Portland cement grade has a relative compressive strength of less than 80 MPa and is typically used in low-strength applications such as grout or paste fillers.
Ordinary Portland cement grade has high porosity, allowing for good workability, low water demand, and fast strength development. The high sulfate resistance allows the concrete to be used in applications with many different types of aggregate finishes. This type of cement grade also has very high durability, allowing for long-lasting infrastructure. Finally, it has the ability to withstand sulfate attack that is superior to other types of cement even at elevated temperatures/concentrations of sulfates (e.g., seawater).
Portland Pozzolana Cement (PPC)
Portland pozzolana cement, or PPC as it is often called, is an extremely popular cement. It consists of pozzolanic ash activated with lime. The pozzolanic properties are what make this type of cement so unique and crucial to the construction industry.
PPC has almost twice the compressive strength of conventional cement but only half the density. This high compressive strength accounts for its use in one-third of all modern concrete structures.
The pozzolanic materials used in PPC are ancient volcanic ashes found in many different areas throughout history. One common pozzolan source currently being mined is trass from Kimble County, Texas, USA.
PPC can be used wherever the pozzolanic properties of this type of cement are needed. PPC is usually formed into grey concrete and used in the construction of large buildings like highways, dams, bridges, airports, etc. Applications have even been found in the field of medicine when pozzolana cement is mixed with non-hydraulic binder components to produce composite bone cement which is stronger than human bones themselves.
Powdered pozzolana cement can also be added to traditional Portland cement during the production process in order to allow for a reduction in the amount of limestone being used while still maintaining most pozzolanic properties.
Because pozzolanic materials are mined all over the world there is a large supply of pozzolana cement; however, they are still very difficult to produce and may not always be readily available.
Hydrographic cement is a special kind of liquid that can be applied to the surface of an object in order to create illusions. The hydrographic process, also known as ‘dipping’, involves submerging objects into tanks containing this liquid and then peeling it off after it has dried so that intricate designs are created on the surface. This design will have the appearance of being painted on with careful precision.
The process is used for painting things like cars, motorcycles, skateboards, surfboards, etc., but these are just some common examples.
The liquid itself consists of several different components which must be mixed together in precise ratios if they are going to create the right consistency. Generally speaking, there are three different types of components that hydrographic cement is made from:
The first thing to mention with regards to the ingredients is how they are categorized. The solvent is a substance that dissolves or separates another substance, so in this case, it will dissolve the solid resin and allow it to be mixed with the surfactant, which acts as an emulsifier (a substance that produces or stabilize an emulsion), creating a consistent mixture that can then be painted onto objects using various techniques. Some common solvents include mineral turps and white spirit. Resin, on the other hand, is a gluey substance created by certain trees and plants. It is also used in the production of plastics – another good example of its gluey properties can be seen when chewing gum is stuck to your shoe.
Surfactant, the third ingredient, refers to a substance that skims the surface of liquids. This means that it reduces their tension, resulting in better wetting (wetting is where one liquid spreads on another liquid). A widely used surfactant in hydrographic processes is PVA, which can bind with itself once it has dried due to strong intermolecular forces between molecules.
Rapid Hardening Cement
Rapid hardening cement is a kind of cement that has the ability to set quickly, within one hour. The product can be used in both construction and industrial applications. It is commonly used to thicken slurry or mortar admixtures.
Rapid curing properties are achieved through the use of blended hydraulic cement, accelerators, superplasticizers, retarders, pozzolans, and other additives.
Typical components include calcium chloride or calcium nitrate as the accelerator; sodium silicate as an additive for producing chemical reactions between water and tricalcium aluminate phases found in certain types of Portland cement; polycarboxylates (e.g., citric acid) as superplasticizer; also fly ash (a pozzolan) is often used.
Rapid hardening cement is synthetic hydraulic cement, which means it consists of calcium, silicon, and oxygen. The product has high water demand because the chemical reaction between calcium hydroxide and tricalcium aluminate usually takes place in the presence of a large amount of water.
The product can be produced on a continuous basis using a rotary kiln or open-hearth methods by mixing limestone, clay, shale, iron ore, bauxite (aluminum ore), fly ash (most commonly used pozzolan), metakaolin (kaolinite clay treated with sodium bisulfate) or silica fume with other additives according to the requirement of rapid hardening properties.
Rapid hardening cement is mainly used in construction and industrial applications that require quick setting. For example, pure rapid hardening cement is blended into ready-mix concrete to reduce water demand, increase early strength development (for traffic control), and shorten the mixing time. The product can also be mixed with Portland cement to produce super-plasticized concrete. For road construction or waste containment, it is usually combined with aggregates such as crushed rocks or sand; this mixture is known as trench silo mix. The product can also be mixed with gypsum powder (stabilizer) to form a thin-set for tile adhesives. Additionally, rapid hardening cement may also be used in the plastic manufacturing industry for improving the properties of plastic.
Sulfates Resisting Cement
Sulfates, also known as sulfate minerals, Sulfates consist of Sulfur combined with one or more metals.
Sulfates resisting cement is a new kind of material that is created by adding certain chemicals into the production process. The Sulfates resisting cement contain the following substances: Sulfuric acid, Sodium sulfate, and Calcium oxide. This mixture hardens to a hard material when mixed with water.
Since Sulfate is an electrolyte in nature, Sulfates resisting cement have high resistance to penetrating acidic corrosion from Sulfated materials such as gypsum and anhydrite which can be used in place of Portland cement, instead of using aggregate stone-like traditional Portland cement (PPC), they use Sulfate resisting cement. Sulfates resisting cement are commonly used as an alternative to PPC for the manufacture of different construction products.
Quick Setting Cement
Quick setting cement is a type of cement that sets quickly after it has been mixed together with water or other liquids. The main purpose of quick setting cement is that it should be able to gain strength within a short time period after it has initially been poured into place and should ideally reach its final required strength in 24 hours. This means that the construction will progress quickly and safely as well as economically compared to using regular cement which takes several weeks to harden.
There are different types of quick-set cement with different constituent materials, resulting in a range of properties. The most common ingredients of a quick-set cement are calcium chloride, zinc chloride, calcium nitrate, ammonium sulfate, aluminum sulfate, and water glass (sodium silicate). Quick set cement may also contain other chemicals to improve the workability or final properties.
It can also be used for cast-in-place applications or precast concrete products where speed is important. The possible applications include building construction, road construction repair, waterworks, etc. It can be applied by pouring it into place or using pre-packaged cartridges.
Low Heat Cement
Low heat cement is a form of cement that has a low heat setting time and low curing time. It is applied and used in conservation and restoration and can be taken at very low temperatures allowing it to bond properly to the structure being repaired. Low heat cement is manufactured with the addition of agents that strengthen their chemical bonds, meaning they have a lower water-cement ratio than other types of cement, such as regular Portland cement (1:2).
Low heat cement was first used to repair historic structures during opera house restorations in Vienna, Austria. It is also well known for its use in repairing large building cracks, leveling out uneven walls that are caused by subsidence or any other ground movement, replacing deteriorated external masonry decoration, or in the restoration of historic stonework. One such example is when it was used to restore a tower in Florence after it suffered damage during an earthquake.
The production process involves several steps. First, selected aggregates such as silica sand or crushed stone are carefully weighed and added to water in order to avoid any variability during mixing. Next, the appropriate amount of lime is added; this is usually between 10%-20% by weight of aggregate and 2%-5% by weight of cement. This low heat cement is completely cured and ready to be applied after 30 minutes and can be set in 10 days, compared with regular Portland cement which takes 90 minutes to achieve the initial set and 28 days for complete cure. The use of this kind of cement can help reduce waste as it has a longer working time than other cement and minimizes the amount of material needed as it is mixed with water on site.
Expansive cement is a type of cement that reacts to heat, water, and sometimes the atmosphere to enlarge.
Ingredients of Expansive cement can include expansive clay or shale, pozzolana, marl, volcanic ash, fire clinkers, silica fume, slag, fly ash, metakaolin, rice husk ash (RHA), or pulverized fuel ash (PFA).
The manufacturing process starts with the production of caustic calcined clinker. This involves heating calcium carbonate in rotary kilns at about 1450 degrees Celsius. The result is then mixed with other materials in the proper proportions which are then ground into fine powder particles in ball mills before being given their shape.
In order to make the material work, it needs to be mixed with water and aggregate. Some methods of expanding include heating wing-shaped samples in a drying oven, placing specimens inside a furnace, or immersion in warm water. In this process, calcium hydroxide is formed and can absorb atmospheric carbon dioxide to form calcium carbide which then cracks into acetylene gas along with free elemental carbon. This then produces lime, which when put under pressure will expand and take up more space than it did before
The main uses for expansive cement are pavement, tiling/flooring, and filling voids in masonry.
Expansive cement is very common in construction. It is also used to create sidewalks, highways, bridges, dams, tunnels, large buildings such as malls and stadiums, and freeways. Expansive cement is also used for restoring structures that have been damaged due to earthquakes or floods by injecting the expansive cement into cracks and crevices to fill spaces where water has entered. Once it has dried the material becomes extremely strong.
Blast Furnace Slag Cement
Blast furnace slag is a byproduct of the blast furnace process, which means it has an abundance of calcium aluminate. It can be used to create cement with many similar qualities to portland cement but without the corresponding negative environmental impacts.
Blast furnace slag cement’s non-porous nature makes it particularly suitable for use in water treatment facilities and swimming pools, as well as minimizing heat loss, reducing erosion along shorelines, and increasing surface durability. It also requires less energy to produce than portland cement due to its two main components being blast furnace slag and limestone. Blast furnaces are powered by fossil fuels such as coal or oil; one tonne of portland cement produces approximately one metric tonne of carbon dioxide, but one tonne of blast furnace slag cement produces approximately 650 kilograms of carbon dioxide – a 50% improvement.
In addition to its use as a component in cement, blast furnace slag is also used as a replacement for sand or gravel aggregates. It can be mixed with water and poured into a mold to create any shape desired, which allows the creation of aesthetically-pleasing features such as benches, tables, handrails, and other civil infrastructure without the need for an elaborate mold. Some cell phone models have been created from 100% recycled materials, including their casings which were made from blast furnace slag. The material has high acid resistance due to its low pH level (3) and is therefore useful in creating long-lasting decorative pieces, such as countertops.
Although the production cost of blast furnace slag cement is higher than traditional portland cement, its reduced environmental impact and long lifespan make it a more sustainable alternative.
High Alumina Cement
High alumina cement is a material that consists of about 70% – 80% fine particles of aluminous bauxite or aluminum trioxide. The remaining 20% to 30% are composed primarily of calcium, silicon, and iron oxide along with small amounts of other ingredients. High alumina cement has chemical properties similar to those of portland cement but its physical properties are significantly different because the high proportion of aluminous compounds gives it superior heat resistance.
High alumina cement is produced by calcining an intimate mixture consisting mainly of hydrated aluminum oxide (Al(OH)3), calcium carbonate (CaCO3), and magnesium carbonate (MgCO3). A reducing agent such as coal, coke breeze, magnesium, or heavy petroleum is used to reduce the iron content of the aluminum trioxide.
High alumina cement can be used as high-temperature refractory material for furnace linings, plugs, and valve bodies. It is also used in fire-resistant bricks and monolithic (cast-in-place) foundry cores.
High Alumina Cement has many uses but the top three are outlined below:
- Furnace Linings
- Fire Bricks
- Foundry Cores
Additionally, it can be sprayed onto metal castings to modify their properties. Other Industrial uses include core boxes for sand casting molds.
White Cement is a type of cement, or concrete powder mix, that has an off-white color to it.
There are various types of White Cement, all differing in their specific formulations of the 3 main components. These 3 main components can be simply described as sand (aka silica), limestone, and clay. Other additives not considered “main ingredients may include but are not limited to: gypsum, aluminum oxide, quartzite, ground granulated blast furnace slag (GGBFS), calcium aluminate cement, air entertainers/water reducers, superplasticizers/air-entraining admixtures, etc., depending on the desired properties for the final product.
The mixture of these compounds with water creates a cement, which can then be combined with a variety of aggregates to create a specific type of White Cement.
The most common use for White Cements is as an additive to mortar and concrete. This allows them to fill in pores and gaps between aggregate particles, which decreases the porosity/voids in the final product allowing for more limestone filler material within the mix, thus creating stronger mixtures with improved resistance to weathering and chemical degradation.
Colored cement is a type of cement that is used as an architectural feature as well as in some household applications. It has been around for nearly a century, and it can be considered a specialty product due to the fact that most coloring agents have only recently been developed for this application.
The types of colored cement on the market today are divided into two categories: pigmented cement and reactive cement.
Reactive cement contains either metallic compounds or metal oxides that form new phases with calcium hydroxide present during the setting process, thus creating richly colored products. In addition to calcium hydroxide, other chemicals such as tricalcium aluminate, dicalcium silicate hydrates (C-S-H), and calcium aluminate cement are often added to reactive cement.
Pigmented cement contains additives that do not require the addition of water during preparation. Instead, pigments are dispersed within the cement matrix, creating color with minimal shrinkage or cracking compared to other methods.
During the production of colored cement, raw materials such as silica sand, limestone, clay, iron ore powder, bauxite (aluminum ore), and dyes are first mixed together in specific proportions before being ground into a powder for further use. Some producers also add various types of fibers to increase strength and decrease cost without increasing weight too much. These fiber products may come from recycled bottles or t-shirts if they are available locally; otherwise, they may be purchased from outside suppliers.
After assembly, the powders are dry-mixed at a high speed for 10–15 minutes using specialized equipment to ensure even distribution of color. The product is then passed through an air classifier in order to remove any oversized particles which could hinder performance during the setting time.
Cement production has recently become more environmentally friendly thanks to the development of coloring agents that do not require a lot of energy or materials for processing into a final product. Some colored cement on the market today has been created with little more than sand and some dyes while others may have additional ingredients such as pigments or reactive chemicals. In general, these types of cement offer superior strength.
Air Entraining Cement
Air Entraining Cement is a type of cement used in the construction industry. It can be used as concrete masonry and stucco and, when it hardens, creates small air spaces that decrease the weight and strength. The main ingredients include water, chemical admixtures, Air entraining agent, Retarder, Superplasticizer, Foaming agent, and Accelerator.
The purpose of these additives is to increase fluidity, durability, and workability through thixotropy, slump retention, air entrainment, or delayed setting time. This means that additives are added to cement to produce better qualities. If an additive causes the cement to flow without compressing then this is known as ‘thixotropy’. This is observed to occur when the water activity is above 0.85 or at a higher amount of cementing materials as well as increased use of admixtures that have no effect on strength such as water reducers and superplasticizers. Water should not be present during mixing but if it is, thixotropy causes the slurry to adhere together so it can be transferred better through pipes along with a slump loss which should not exceed five percent. Thixotropic materials are added to increase the viscosity of the substance by increasing its yield value until complete solidification, also known as ‘delayed setting’. Other additives like air-entraining agents prevent shrinkage cracks in concrete by allowing small amounts of air bubbles to be integrated into the material. Materials that are commonly used for thixotropic agents include guar gum, xanthan gum, and fumed silica. Thixotropic materials consist of polysaccharides that have a molecular weight of fewer than 50,000 Daltons. Air entraining agents cause the concrete to create small air bubbles when it hardens which prevents cracking by filling in space between irregular surfaces within the concrete. The volume of these cementing admixtures is up to six percent while superplasticizers contain 10-20 percent water [as hydrate] and 0-2 percent plastic material. Retarders increase the time required for a hardened product to be achieved while accelerating causes a quick reaction resulting in a quicker setting.
Masonry cement is a type of mortar used in masonry construction. It’s made largely of portland cement, water, and some sort of additives like lime or clay. Some masons might use premixed bags of mortar (though this practice is becoming more uncommon), but many mix their own using powdered portland cement, sand, and other additives.
Mortar makes the bond between bricks possible by filling the gaps that would otherwise be filled with air. However, even though mortar holds bricks together, it isn’t really part of the brick structure itself–rather than forming one solid mass as concrete does, mortar allows some movement within the wall while still holding everything together. This makes it easier for older buildings to stand without additional support while still allowing the bricks to shrink and expand at different rates from season to season.
Masonry cement is typically composed of fine aggregates, such as sand or crushed stone; hydraulic cement, typically portland cement; and an additive like lime or clay which can be used to change how it sets up. Each ingredient serves a certain purpose in the mortar, and there are different formulations depending on what kind of job you’re going for. Some additives increase workability while others make your mortar more waterproof. Fine aggregate makes the mixture bulkier in order to create space for water molecules in between each solid particle (which helps with cohesiveness). This gives you a strong concrete-like density without making your mortar brittle.